This pen holder took over 7 hours to print. This pen holder took less than 4 hours to
print. It's the same STL. And it's even five grams
heavier so it's not because it uses less material - it uses more.
Let's explore what's going on here.
Intro.
Usually whan you want to reduce the print time of a piece you try to reduce the walls,
reduce the infill, I mean if you want to go extreme with cylinders like this you could
go to vase mode and try to make a thick width single wall vase - video on that coming in
the future.
But this video is about an oddity I found that makes sense once you know, but it's still
quite fascinating and worth remembering.
Let's take the model into cura and have a look at it, it's just a standard cylinder
- I made this for the end of my last video on using sugru at the base to stop it scratching
a desk, so it has this profile to hold the sugru at the bottom. It could have done with
being a lot wider but that's beside the point.
If I choose my usual fast profile and 2 walls which is pretty standard, and slice it, I
get 7 hours and a few minutes. It's not that surprising for a fairly tall model but it's
still more than I might expect.
By chance I changed the wall count to THREE, and look what happens. Under four hours.
Why.
Whenever I'm not sure why a print time is longer than it ought to be, I find this report
useful on cura. There's a similar one on prusaslicer, in cura you hover over the i symbol, this
is fairly recent in cura actually so if you're running an old version you won't have it.
You can see here that in the shorter one you have two minutes of infill versus the longer
one at 27 minutes. So that explains half an hour, which you'd expect, more walls, less
infill. But the key here is you've taken ALL the infill out which means you're not having
to travel doing the infill which turns out to account for a whopping nearly three hours!
It's also interesting to see how the other variables line up, three walls means you don't
spend nearly as much time on skin, but more time on inner walls, which I can't say makes
a lot of sense, in spite of trying to look up what "skin" is in terms of cura, I didn't
get anywhere - as usual if you know please comment. At a hunch it's just the outermost
wall which is labeled as "shell" in the preview here. I know prusaslicer uses shell instead
of skin. Oh for consistent terminology.
But yeah the main cause of the delay isn't the infill, it's the travels. Let me put the
previews side by side here and you can see. Look at all the blue lines - these are travels.
I guess the type of infill will determine how many travels but the point I want to make
here is that the three wall version is essentially working way more efficiently even though it
has more filament to lay down. It only travels what, a maximum of five times per layer by
the look of it.
This is definitely a technique to keep in mind every time you're printing something
out that's essentially a container, so that might be a cup shape like this, or maybe drawers
for a storage box, or any kind of case like this one for trading cards. If you can eliminate
the infill in the sides by increasing the walls, then you will save time, and perhaps
even wear and tear on the printer too.
I suppose you might be screaming at this point that this is basically the same as 100% infill
and you'd be right, but it's not entirely. If you did 100% infill, you'd be including
tops and bottoms of objects which may even degrade quality and wastes another 14 grams.
It's never a good idea really to print at 100% infill unless you know what you're doing...I'll
jot that discussion down for a future video.
So I hope this was helpful, I guess the moral of the story is that more is less, or less
is more, or maybe just to always have a good look at the preview before you print.
Subscribe if you like this sort of thing, and I will see you next time. Thank you for
watching.